Self-registering thermometer



(No Model.)

W. H. H; BARTON.

SELF REGISTERING THERMOMETER.

N0.289,603. I Patented Dem l, 1883.

.AT'IIORKE Y S.

s iholciilllognuhcr. Washington. D. c.

. thereto.

idly attached bimetallic strips 0 O, in the usual UNITED STATES? PATENTOFFICE.

WILLIAM H. H. BARTON, or BROGKTON, MASSAOHUSETTS.

SELF-REGISTERING THERMOMETER.

SPECIFICATION forming part of Letters Patent No. 289,603, dated December4, 1883. Application ma August 1'1, 1883. (No model.)

To all whom it may concern:

Be it known that I, WILLIAM H. H. BAR- TON, a citizen of the UnitedStates, residing at Brockton, in the county of Plymouth and State ofMassachusetts, have invented certain new and useful Improvements inSelf-Registering Thermometers, of which the following is aspecification.

This invention relates to automatic recording-thermometers; and theobject of it is to continuously record the various fluctuations in thetemperature of the atmosphere and to form a permanent record thereof;and to this end my invention consists in pivoting a long lever or armdirectly to the free ends of the bimetallic strips of a metallicthermometer, so that any contraction or expansion of the bimetallicstrips incident to the changes in temperature will cause the lever tovibrate. The outer end of the lever is provided with a tracing-needle orother suitable means for indicating or tracing the vibrations on asuitable chart which is supported in an upright frame at a properdistance from the end of the lever, and the chart is moved by achronometer mechanism across the path of vibrations of the lever.

As illustrating the details and mode of constructing the apparatus forthis purpose, reference is to be had to the accompanying drawings,forming a part of this specification, in which similar letters ofreference indicate corresponding parts in all the figures.

Figure 1 is a perspective view of my improvement, and Fig. 2 is a sideview of the same, the lever-arm being represented in different positionsby .the dotted lines., Fig. 3 is an enlarged detail view of the jointconnecting the strips with the lever.

The base or frame Ahas atone end a raised circular portion, B, to whichis attached an upright post, G. To one side of the post, secured bymeans of a metallic plate, are two studs or posts, H H. These studs orposts are close together, one slightly above the other, and project fromthe upright G at right angles To these posts or studs H H are rigmannerof constructing thermometers of this kind. In the outer ends of thestrips 0 G are slats c 0, through which the lever I is passed andconnected to the metallic strips 0 O, as

will now be described. The leverI is formed of two parts-the outer part,I, to the end of which is pivoted the tracing-needle, and the innerpart, 1*, which is provided with a movable weight, I The two'parts ofthe lever I are connected by means of a rectangular bar, K. The bar Kpasses through the slots 0 c in the metallic strips 0 O, and is pivotedto the strip 0 by means of a pin, J, which is supported or journaled inlugs j j on the inside of the" metallic strip 0. The bar Kis providedwith a slot, This slot is long and narrow. The strip 0 is also providedwith lugs j 3' on the inside, similar to those on the strip 0, andthrough these lugs and the slot 70 is passed a pin, J. The lever I beingpivoted to the strip 0 by means of the pin J, passing through therectangular bar K, and journaled in the lugs j j, and connected to thestrip 0 by the pin J, passing through the slot is, the pin J forms amovable fulcrum, and any contraction of the bimetallic strips 0 G forcesthe outer end of the lever upward and any expansion forces the leverdownward.

- L is a tracing-needle, which is pivoted at the end of the lever I. Theupper end of this needle is preferably weighted, so as to keep its pointconstantly against the chart-and to offset any contraction of thelever-arm, the needle being pivoted so that the weight tends to throwits lower end outward. The needle itself may be weighted, or it may beprovided with an adj ustable ball.

Instead of the needle L,a pencil or pen may be pivoted in the samemanner.

The object of the sliding weight I on the inner end of the lever is tobalance the same and to adjust it in relationto a scale hereinafterdescribed.

M is an upright frame, provi dcd with grooves m m.

N is a bar or plate, having a groove, n, on its upper side and teeth aon its edge, as shown.

0 is a suitableclock-work mechanism,which operates the pinion'o. Theteeth of the pinion 0 mesh with the teeth n of the bar N, and as theshaft on which the pinion is mounted is rotated by the clock-workmechanism motion is thus communicated to the slide or bar N, which ismoved across the base of the frame.

Mounted in the groove on on the bar N is a suitable chart, 1?, which maybe a smokedglass plate, a smoked or plain paper chart, or

any other suitable material for receiving the impression made by thetracing needle, pen, or pencil. This chart or glass plate, as the casemay be, is slightly concaved on the inner side, in order to be inrelatively the same arc of a circle as that described by the vibrationof the lever-arm. The upper edge of the chart slidesin the groove m inthe frame. As

the chart is rigidly attachedto the bar N, it is moved by the clock-workmechanism across the face of the tracing-needle.

Instead of the sliding plate or bar Nsliding in the groove m in theframe, it may be mounted upon rollers; or other suitable mechanism forthis purpose may be used.

R and S are two scales, which are used to designate the differentdegrees of temperature and the space over which the chart is moved; butinstead of these scales prepared plates or charts having suitableregistering-lines may be used.

Having described my invention, its operation is as follows: The leverhaving been properly adjusted and the clock-work regulated to move thechart at the desired rate of speed, the tracing-needle on the end of thelever bears slightly against the chart,which is so prepared as to besensitive to the slightest impression. Any contraction or expansion ofthe bimetallic strips vibrates the lever, and these vibrations aretraced upon the chart (which is moved by the clock-work mechanism) bythe tracing-needle, which makes a continuous record in diagram form ofthe temperature at different periods of time. Of

course the greater the length of lever usedthe greater the length ofVibration and the more delicate will be the fluctuations recorded.

Having thus fully described my invention, what I claim as new, anddesire to secure by Letters Patent, is-

1. The combination of the metallic strips 0 C, with the lever pivoted toone of said strips and connected to the other strip by means of the pin,and the slotted bar K, so as to have a movable fulcrum, substantially asand for the purpose set forth.

2. An automatic recording thermometer having a lever pivoted to themetallic strips G O, carrying on its inner end the sliding weight and onits outer endthe pivoted needle, pen, or pencil, the inner end and theouter end of the lever being connected by means of a slotted bar, K,substantially as and for the purpose set forth.

3. Thecombination of the bimetallic plates, slotted as described, thelever pivoted therein, and provided at its outer end with a tracingneedle, pen, or pencil, and its inner end with the movable weight, themovable slide or bar N, the concave chart, the clockwork mechanism,pinion O, and the scales R and S, all substantially as and for thepurpose set forth.

In testimony whereof I affix my signature in presence of two witnesses.

IRA A. LnAcn, SIMEQN L. MILLARD.

